Radio signal noob looking for information on what to look at on signal quality…
We have recently finished our setup with a few nodes and a custom gateway.
it’s now time to test range and performance, fun starts now
in Canada so we are in 915Mhz ranges.
We are receiving most if not all message while inside, but we did a small car trip and lost 99% of messages.
I’ve tested different antennas and looking at event log I’m looking at numbers witch dont mean a lot to me.
I’m curious if anyone as great detailed (understandable, straightforward ) links / books or other resources on the ‘good’ numbers to get for a strong and reliable signal. RSSI, SF, codeRate, )
right now with my most expensive antenna
I get -120 rssi, -2,2 loraSNR, on a spread factor 7
not even sure those are the numbers I should look at.
tested this one;
and got -34 rssi… meaning it’s really bad compared to the other antenna ?
I know spec mentioned a LTE antenna but the frequency range stated 698 – 960 so I thought I give it a try…
seeing a few video on longest range https://www.youtube.com/watch?v=adhWIo-7gr4
Andreas is focusing on those… but I’d like to know where to focus for my testings and compare numbers that are worth looking at…
what would be the good and bads… What are the things I should focus on ?
Hi, If you get -120 on one antenna and -34 on another in same place that means that your first antenna is completely non working (-120 is worse than -34). You may try without antenna at all and probably will get same results. Looks like antenna is broken. I bet if you try piece of wire with length 86 mm you’ll get much better results.
do you have reading suggestions on that subject ?
@GMtl Have you made any headway with your tests? I had meant to respond earlier but it got lost with everything else I have been doing recently.
Assuming from your username you are in the Montreal area, were your tests on the island downtown or off island in one of the suburbs?
I’ve been able to reliably get 5km south of Montreal for my work with just the simple cheap antenna that came with the node shield and gateway board. My gateway is indoors albeit near a window/exterior wall on a second floor. I’m waiting to be able to test my nicer antennas when things calm down a little bit here but I’m hoping to improve that distance and I’ll be able to test the gateway antenna at a 30m height. I also have a simple gateway at my apartment in the city but I haven’t really tested it for distance besides just testing my nodes to make sure the instrumentation is set up and sending properly.
I unfortunately don’t have any RSSI values to share at the moment but hopefully I’ll be able to get you some if you’re interested from my cheap-o antennas.
Hi, @geofbaum, yea I’m in Montreal.
My office is in ville saint-Laurent near 40/13.
I’ve received one antenna and placed on the top of our warehouse roof
not the highest around but still clearing a lot of neighbors
until now, I’ve tested only in one direction since I had other project to finish.
Got only 1,1 mile max in that direction.
the blue dot line is the far I can go…
I,ll do more testings soon and keep you updated.
I’m also considering Ubiquity antennas… they look nice.
the AM-9M13 looks great spec at 900mhz
I’m also waiting for a new node that has GPS module so it will ease my job, driving around and let the server send gps location … when I get back I could simply track it down and see where signal is good and where it’s not.
Yeah I would expect you’d be able to get a bit better distance from your location than 1,1 miles but there could also be some other things in the area broadcasting the same frequency for all I know.
As far as using that Ubiquiti antenna, it probably would work but I’ve only had experience with Ubiquiti products for transmitting a network connection and for that the antenna and the radio are all one unit which is nice that I don’t have to purchase an antenna and a BaseStation.
As for other antennas I’ve used for other applications (namely transmitting data from a weather station, and other sensor nodes with an Xbee), I’ve used the following omni-directional antenna:
And a varient of it from another company that I was given for testing. They seem to work well for what I need them to do, and one of the ones that I have pairs well with this yagi variant for my relay stations.
@geofbaum, yea, I have a lot of big antennas around our offices and a lot of high voltage power lines…
more test to come. different antennas too.
but climbing on that roof from outside is not my preferred activity
my gateway is not yet waterproof so I have a +/-30ft coax wire going to the roof antenna… I know it’s not the best.
Hi All, what do I need to buy (or build) to test the signal pattern? I’d like to see if its performance matches MMANA’s predictions, but I don’t know how to go about it. Just testing with repeaters and S-meters seems really sloppy. What equipment, physical space, and procedures do I need to figure out if the lobes are where they’re supposed to be, and measure the gain? Any traps for younger players I need to watch out for?